Ratio to Fraction and Percent Calculator
Convert a ratio like 3:2 into a simplified fraction, a decimal and the percentage share of each part of the whole.
How it works
Whole = a + b · a-fraction = a ÷ (a+b) (reduced) · a-share % = a ÷ (a+b) × 100 · a:b decimal = a ÷ b
A ratio a:b compares two parts, and turning it into a fraction of the whole means dividing each part by the total a + b. That fraction, reduced by the greatest common divisor, converts straight to a percentage by multiplying by 100. The a-to-b decimal (a ÷ b) is a different view — how many times bigger the first part is than the second, rather than its share of the total.
Worked example
For the ratio 3:2 the whole is 5, so the first part is 3/5 = 60% and the second is 2/5 = 40%. As a direct comparison, 3 ÷ 2 = 1.5, meaning the first part is one and a half times the second.
Sources: Ratio — Wikipedia
Frequently asked questions
Should I use a ÷ (a+b) or a ÷ b?
Use a ÷ (a+b) for the share of the whole — the percentage that adds up to 100% across all parts. Use a ÷ b when you want the ratio as a single multiplier showing how the two parts compare directly.
How is the fraction simplified?
The calculator divides both the numerator and denominator by their greatest common divisor, so 6:4 becomes 6/10 = 3/5 rather than staying as an unreduced fraction.
Do the two percentages always add to 100%?
Yes, for a two-part ratio the shares are complementary and sum to 100%, because together the parts make up the whole.
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This calculator is for educational purposes. Double-check important results before acting on them.